Characteristics of freezing of gait in community dwelling people with Parkinson's disease.

Background: Freezing of gait (FOG), a feature of Parkinson's disease (PD), increases with disease progression. The incidence of FOG remains unclear especially in the early stages of the disease. Aim(s): (1) To characterize FOG in people with PD who live in the community; and (2) to investigate the relationship between the frequency and severity of FOG with duration and severity of disease. Method(s): 210 community dwelling people with PD, stages 1 to 4 Hoehn and Yahr (H&Y), with a MMSE score of 24 or greater and the ability to participate in exercise programs were included in a RCT investigating the effect of exercise on mobility and falls. Baseline data from the freezing of gait questionnaire (FOG-Q) [1], the H&Y scale and disease duration were used in this study. Descriptive statistics characterized the FOG episodes and Spearman's correlation coefficient was used to examine the relationship between FOG frequency (question 3 of the FOG-Q) and FOG severity or duration of FOG episodes (question 4 of the FOG-Q) with both duration (years since diagnosis at time of testing) and severity of disease (H&Ystage). Result(s): 28% of the 54 people who had PD for 2 or less years reported freezing of gait. The number of people who reported FOG was greatest in those who had a longer duration of disease, with 84 % of the 38 people who had PD for > 10 years experiencing freezing. The number of people reporting freezing episodes increased across the H&Y stages, with only 31% of people at H&Ystage 1 or 2 reporting FOG, compared to 79% of people with H&Y of 4. Of the 107 participants who reported freezing, 89% experienced FOG at step initiation and 73% on turning. There was a significant relationship between the frequency of FOG and both disease duration (rs=.42, p<.001) and disease severity (rs=.43, p<.001). Severity of FOG was significantly correlated with PD duration (rs=.46, p<.001) and disease severity (rs=0.44, p<.001). Conclusion(s): Even though FOG was associated with disease